From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758566AbZE2RQa (ORCPT ); Fri, 29 May 2009 13:16:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753629AbZE2RQW (ORCPT ); Fri, 29 May 2009 13:16:22 -0400 Received: from hera.kernel.org ([140.211.167.34]:57502 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752505AbZE2RQV (ORCPT ); Fri, 29 May 2009 13:16:21 -0400 Date: Fri, 29 May 2009 17:15:45 GMT From: tip-bot for GeunSik Lim To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, geunsik.lim@samsung.com, leemgs1@gmail.com, rostedt@goodmis.org, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, geunsik.lim@samsung.com, a.p.zijlstra@chello.nl, leemgs1@gmail.com, tglx@linutronix.de, mingo@elte.hu In-Reply-To: References: Subject: [tip:sched/core] ftrace: fix typo about map of kernel priority in ftrace.txt file. Message-ID: Git-Commit-ID: 294ae4011530d008c59c4fb9847738e39228821e X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Fri, 29 May 2009 17:15:47 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 294ae4011530d008c59c4fb9847738e39228821e Gitweb: http://git.kernel.org/tip/294ae4011530d008c59c4fb9847738e39228821e Author: GeunSik Lim AuthorDate: Thu, 28 May 2009 10:36:11 +0900 Committer: Ingo Molnar CommitDate: Fri, 29 May 2009 16:21:08 +0200 ftrace: fix typo about map of kernel priority in ftrace.txt file. Fix typo about chart to map the kernel priority to user land priorities. * About sched_setscheduler(2) Processes scheduled under SCHED_FIFO or SCHED_RR can have a (user-space) static priority in the range 1 to 99. (reference: http://www.kernel.org/doc/man-pages/online/pages/ man2/sched_setscheduler.2.html) * From: Steven Rostedt 0 to 98 - maps to RT tasks 99 to 1 (SCHED_RR or SCHED_FIFO) 99 - maps to internal kernel threads that want to be lower than RT tasks but higher than SCHED_OTHER tasks. Although I'm not sure if any kernel thread actually uses this. I'm not even sure how this can be set, because the internal sched_setscheduler function does not allow for it. 100 to 139 - maps nice levels -20 to 19. These are not set via sched_setscheduler, but are set via the nice system call. 140 - reserved for idle tasks. Signed-off-by: GeunSik Lim Acked-by: Steven Rostedt Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- Documentation/trace/ftrace.txt | 15 ++++++++++++--- 1 files changed, 12 insertions(+), 3 deletions(-) diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index fd9a3e6..e362f50 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -518,9 +518,18 @@ priority with zero (0) being the highest priority and the nice values starting at 100 (nice -20). Below is a quick chart to map the kernel priority to user land priorities. - Kernel priority: 0 to 99 ==> user RT priority 99 to 0 - Kernel priority: 100 to 139 ==> user nice -20 to 19 - Kernel priority: 140 ==> idle task priority + Kernel Space User Space + =============================================================== + 0(high) to 98(low) user RT priority 99(high) to 1(low) + with SCHED_RR or SCHED_FIFO + --------------------------------------------------------------- + 99 sched_priority is not used in scheduling + decisions(it must be specified as 0) + --------------------------------------------------------------- + 100(high) to 139(low) user nice -20(high) to 19(low) + --------------------------------------------------------------- + 140 idle task priority + --------------------------------------------------------------- The task states are: